path: root/fs
diff options
authorDeepa Dinamani <deepa.kernel@gmail.com>2016-09-14 07:48:02 -0700
committerAl Viro <viro@zeniv.linux.org.uk>2016-09-27 21:06:20 -0400
commit3cd886666ff19e9796a519e16d94fc94f79c8a4c (patch)
tree24f3f8f94734d44bf369ebfd8ef7189d1f5a9972 /fs
parentLinux 4.8-rc6 (diff)
vfs: Add current_time() api
current_fs_time() is used for inode timestamps. Change the signature of the function to take inode pointer instead of superblock as per Linus's suggestion. Also, move the api under vfs as per the discussion on the thread: https://lkml.org/lkml/2016/6/9/36 . As per Arnd's suggestion on the thread, changing the function name. current_fs_time() will be deleted after all the references to it are replaced by current_time(). There was a bug reported by kbuild test bot with the change as some of the calls to current_time() were made before the super_block was initialized. Catch these accidental assignments as timespec_trunc() does for wrong granularities. This allows for the function to work right even in these circumstances. But, adds a warning to make the user aware of the bug. A coccinelle script was used to identify all the current .alloc_inode super_block callbacks that updated inode timestamps. proc filesystem was the only one that was modifying inode times as part of this callback. The series includes a patch to fix that. Note that timespec_trunc() will also be moved to fs/inode.c in a separate patch when this will need to be revamped for bounds checking purposes. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
1 files changed, 23 insertions, 0 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 7e3ef3af3db9..2172d0f77011 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -2049,3 +2049,26 @@ void inode_nohighmem(struct inode *inode)
mapping_set_gfp_mask(inode->i_mapping, GFP_USER);
+ * current_time - Return FS time
+ * @inode: inode.
+ *
+ * Return the current time truncated to the time granularity supported by
+ * the fs.
+ *
+ * Note that inode and inode->sb cannot be NULL.
+ * Otherwise, the function warns and returns time without truncation.
+ */
+struct timespec current_time(struct inode *inode)
+ struct timespec now = current_kernel_time();
+ if (unlikely(!inode->i_sb)) {
+ WARN(1, "current_time() called with uninitialized super_block in the inode");
+ return now;
+ }
+ return timespec_trunc(now, inode->i_sb->s_time_gran);